What is the rear spacing of your 907? 170 or 135? Alfine has 135 spacing. 170 and alfine can be done, but spacers for the brakes and hub would need to be machined. Chain tension is the other issue that you'll run into. You can try to use a half-link to get you close to a perect fit or consider any number of chain tensioning devises to get the job done.

EDIT: Having done a magic gear bike and it being a royal pain in the ass, I hope your offset frame has sliding dropouts.

or just use a chain tensioner. The clean chainline thing only is awesome when it means robust/hassle free service. When you have to compromise your gear ratios and worry about chain wear all the time you've killed any stoke I'd have for the idea.

Just get a chain tensioner. I use one with a Rohloff on my Big Dummy and it's not a bad solution if you have vertical dropouts.

I have a snow white pugs to use if I can't make the 907 work. My goal is to stop buying derailers for my wife's 907....just sayin'

The Pugs will setup with an A8 IGH no problem. It's the same wheel offset as the 907 so you can try it in the Pugs with a 32T x 23T. If she needs lower gears you can get a 30T ring for a 104 BCD MTB crank if that's what you have.

If she doesn't need the low gears of the 32T x 23T setup you can try VB's 32T x 20T magic gear combo on the 907.

FYI, I ran an Alfine 11 in my 907 this winter. I used an Alfine Chain Tensioner and kept the RaceFace double & bash up front to give me 2x11 gears. If you swap the Alfine alignment washers around you can run the gear cable up the seatstay.

I will probably set it up first on the Pugs. Use it as a test sled. Find the gearing she likes and transfer it over. IF she doesn't like it....I get an IGH Pugs!
Vikb, what non-turn washers for the Pugs. I'll order the non-turn for both the 907 and the Pugs at the same time.
Thanks for the info folks. The members on the fatbike forum have to be the best on mtbr.

Thanks again everyone. I am looking at keeping the "dangle-ly" things away from roots and rocks. A DMR or surly singulator to tension the chain (on the 907) to pull up on the chain. The Pugs won't need it. Man, I love my pugs...just like my 1x1. A blank canvas.